(1) Field of the Invention
The invention generally relates to scissors. More particularly, the invention relates to the use of channel voids within scissor blades and other features to dissipate debris.
(2) Description of the Related Art
Scissors have been known in the related art since the Iron Age. In general, two blades define a pivot void and a contained pivot pin holds the two blades in rotational alignment. The two blades each feature sharpened leading edges that move into each other as the back sides of the blades are squeezed. Scissor blades of the prior art feature planar inside surfaces that smoothly slide upon one another during use. While the smooth planar inside surfaces of the blades and conducive to precise cutting, the smooth inside surfaces are easily fouled with debris when cutting organic matter.
Over the years, many advances have been made in the pivot pin systems that pivotally secure scissor blades. Such advances include the use of screw type pivot pins that allow for precise and lasting adjustment of the friction imposed or tension maintained between the inside blade surfaces. Advances in pivot pins or set screws help scissors maintain consistent cutting performance without premature detachment of the blades. Some modern pivot pin systems allow for consumers to easily disassemble scissor blades for cleaning and precise sharpening.
While there have been advances in the configurations of pivot voids and pivot pins, the prior art fails to address the issue of debris accumulating upon scissor blades and/or within the pivot voids and pivot pins. For example:
U.S. Pat. No. 1,545,211 issued to Storz on Jul. 21, 1922 discloses a pivot piece used to secure two scissor blades in rotational alignment. The Storz pivot insert features an interesting tightening screw system to better secure the pivot pin into the blades.
U.S. Pat. No. 2,382,341 issued to Snell on Aug. 14, 1945 discloses a pin and void system allowing for the blades to be removed after final construction.
U.S. Pat. No. 2,626,460 issued to Sterling on Jan. 27, 1953 discloses a pivot boss system in keeping the blades in pivotal connection.
U.S. Pat. No. 5,421,090 issued to Chiou on Jun. 6, 1995 discloses irregularly shaped leading edges or blade edges used to keep material from sliding off of the blades.
U.S. Pat. No. 5,636,443 issued to Linden on Jun. 10, 1997 discloses a pair of snips using an interlocking blade system to help with the smooth rotation of the blades.
U.S. Pat. No. 6,634,105 issued to Lindermeir on Oct. 21, 2013 discloses pruning shears with means of retaining cutting material close to the blades as coarse bush branches tend to slide off traditional shears. Lindermeir is teaching the confinement of organic material to better cut the material.
U.S. Pat. No. 5,243,762 issued to Orthey on Sep. 14, 1993 discloses garden shears using pivot joint comprising a steel bushing that accommodates shear and flexure loads from the blades. Orthey appears to accommodate the severe forces applied to garden shears but, like the other know prior art, fails to address the need to remove organic matter or other debris.
The Japanese prior art known to date includes:
[PTL 1] Japanese Unexamined Utility Model (Registration) Application Publication No. 05-063467
[PTL 2] Japanese Unexamined Patent Application Publication No. 07-047177
[PTL 3] Japanese Unexamined Patent Application Publication No. 10-179951
[PTL 4] Japanese Unexamined Patent Application Publication No. 2006-181036
[PTL 5] Japanese Unexamined Patent Application Publication No. 08-155157
[PTL 6] Japanese Unexamined Patent Application Publication No. 09-164277
[PTL 7] Japanese Unexamined Patent Application Publication No. 11-221374
Thus, there appears to be a shortfall in the art in that known scissors or shears fail to be self-cleaning or otherwise dispel debris that accumulates within scissor components when cutting organic matter.
For example, gardening scissors or shears used for cutting small branches or for harvesting or thinning out fruits such as grapes tend to accumulate sap, resin or other organic matter upon both the inside blade surfaces and the voids used to secure pins and other means of rotational attachment. Scissor blades are sometimes referred to as shafts or support shafts and pivot voids are sometimes referend to as shaft support holes. Moreover, kitchen scissors used for cutting foodstuff are subjected to fouling between the blades and within the pivot mechanism as foreign objects such as grease and juice are dispersed within the system mechanisms. The smooth planar inside surfaces of prior art scissor blades provide no means of efficient egress for foreign matter.
Shaft section structures of scissors or scissor blades conventionally include a locked shaft type (riveted type) pivot retention system, in which the shaft—for example, a headed rivet—is inserted through the shaft support holes near the centers of the pair of blades, and the tail of the rivet is bucked so that the blades are pivotally supported (see, for example, Patent Literature (PTL) 1 to 4).
In another prior art example, a shaft or blade defines a void wherein a bolt is inserted through a shaft support hole near the center of the pair of blades, and a nut is screwed on to the bolt to pivotally fasten and secure the blades (see, for example, PTL 5 to 7).